In the installation of sheet vinyl flooring material having a polyurethane wear layer, considerable difficulty has been experienced in joining together various strips or sections of the flooring in such a way that the various sections are tightly joined with no seams showing and with the overall high gloss finish of the flooring unimpaired. These objectives have been especially difficult to obtain with sealing compositions which can be applied in a one step operation. For instance, one commercially used system for joining sections of vinyl flooring having polyurethane wear layers involves first using cement such as epoxy cement to join the sections together and then covering the resulting seam with polyurethane. Another known technique involves the use of two package polyurethane prepolymer sealant systems which must be mixed at the point of use. The polyurethanes used are such that they serve to cement the vinyl edges of the adjoining sections of flooring together and also fuse or weld the urethane finishes on the adjoining sections to produce a continuous, smooth, high gloss finish. Both of these systems depend basically on cementing the sections of flooring together and achieve a true fusion or welding effect only with respect to the polyurethane wear layer.
It is also known to use solvents for polyvinyl chloride (PVC), such as tetrahydrofuran (THF), in solution with PVC to join together sections of vinyl flooring having polyvinyl chloride wear layers. Such solutions containing THF function effectively to fuse or weld together the adjoining sections of polyvinyl chloride layers, but attempts to use such solutions on vinyl flooring having polyurethane wear layers have been unsuccessful due to poor appearance and lack of gloss in the areas of the seams.